1. Molecular Engineering and Science Institute University of Washington Seattle WA 98195 USA
2. Materials Science and Engineering Department University of Washington Seattle WA 98195 USA
3. Chemistry Department University of Washington Seattle WA 98195 USA
4. Physics Department Institut für Quantenoptik Universität Ulm Ulm D‐89081 Germany
5. Physical and Computational Sciences Directorate Pacific Northwest National Laboratory Richland WA 99352 USA